Carrier route record
WNFLL→SJU
Southwest Airlines · Fort Lauderdale to San Juan
- Flights
- 279
- Period
- July 2025 to June 2026
- Share of route
- 12%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on FLL to SJU draws a D+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 50 minutes behind schedule. Build slack into anything you connect to. That rests on 279 flights, with a median arrival 4 minutes late.
The national on-time rate over the same period is 77.6%, so Southwest on FLL to SJU runs 13 points behind the country as a whole. Across a thousand flights that is about 129 extra late arrivals.
Key figures
On time
64.7%
Arrivals under 15 minutes late, of 278 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.36%
National rate is 1.81%
Whole route
68.0%
Every carrier on FLL to SJU, 2,344 flights
These figures cover 279 flights between July 2025 and June 2026. Beyond the headline rate, 9.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Southwest against every carrier on FLL to SJU
Southwest flew 279 of the 2,344 flights on FLL to SJU, about 12% of it. Its 64.7% on time is 3 points worse than the route as a whole, which runs 68.0%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from JetBlue at 71.0% to Spirit at 55.4%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airways | 1,646 | 71.0% | 58 min | 1.22% | C |
| Southwest Airlines (this page)thin sample | 279 | 64.7% | 48 min | 0.36% | D+ |
| Frontier Airlinesthin sample | 128 | 64.2% | 110 min | 3.91% | D− |
| Spirit Airlinesthin sample | 291 | 55.4% | 68 min | 1.72% | D |
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am10 flights—
- 8am–11am26 flights—
- 11am–2pm146 flights73.8%
- 2pm–5pm15 flights—
- 5pm–8pm53 flights47.2%
- 8pm–5am29 flights—
Scale runs 40% to 80%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 47.2% on time, against 73.8% for the 11am–2pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 146 flights scheduled in it.
Across the year
Southwest on FLL to SJU through the year
- Jul–Sep 202575 flights65.3%
- Oct–Dec 202591 flights63.7%
- Jan–Mar 202671 flights61.4%
- Apr–Jun 202642 flights71.4%
Scale runs 55% to 75%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 64.7% on time across 279 flights.
Southwest on FLL to SJU did not run the same all year. Its best quarter was Apr–Jun 2026 at 71.4% on time and its weakest Jan–Mar 2026 at 61.4%, a swing of 10 points on roughly 70 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Thursday is the strongest day at 67.4% on time and Sunday the weakest at 41.7%. 26 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 4,656 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 55%Late-arriving aircraft
- 26%Carrier
- 18%National Airspace System
- 1%Extreme weather
55% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 4,656 reported delay minutes here, that single category outweighs weather by 38 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 4,656 reported delay minutes.
Cancellations are rare at 0.36%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.0% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 1,046 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 76.3% on time across 279 flights, 12 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 12 points of difference.
One caution: this is a thin sample. 279 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on FLL to SJU
Put together: treat all of this as provisional. 279 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 64.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 278 completed flights over 12 months sit behind that.
Related
Where to go next
- FLL to SJU, every carrier
- Southwest on SJU to FLL, the return leg
- JetBlue Airways on FLL to SJU71.0%
- Frontier Airlines on FLL to SJU64.2%
- Spirit Airlines on FLL to SJU55.4%
- Southwest Airlines network-wide record
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- Luis Munoz Marin International (SJU) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.